The castle was a bulwark, standing guard against various opposing armies and raiding parties for centuries.

BBC: Forgotten Northumberland

Sheikh Khalifa bin Zayed Al Nahyan was taken on a carriage procession with the Queen to Windsor Castle, where he was given a guard of honour.

BBC: The Queen, Prince Phillip and Sheikh Khalifa Al-Nahyan

He enjoyed a carriage procession with the Queen through Windsor to the castle where guardsmen from the 1st Battalion Welsh Guards in their scarlet tunics and bearskins formed a guard of honour.

BBC: The Queen, Prince Phillip and Sheikh Khalifa Al-Nahyan